In recent years, as one of lighting apparatus instead of an incandescent bulb, an LED bulb using LED begin to come into widespread use. When an LED bulb instead of an incandescent bulb is applied, it is tried to reduce costs for introducing the LED bulb by utilization of wiring equipment and a light dimmer built-in an existing construction.
For example, in a circuit connection to an incandescent bulb, each of an incandescent bulb having two terminals and a triac light dimmer having two terminals for incandescent bulbs are used. One of the two terminals included in the triac light dimmer is connected to a commercial power source, and the other of the two terminals is connected to one of terminals included in the incandescent bulbs. The other terminal included in the incandescent bulb is connected to the commercial power source. Thus, the triac light dimmer and the incandescent bulb are series-connected with the commercial power source.
The triac light dimmer includes, for example, a main power source of the incandescent bulb, an operation unit for adjusting a luminance of the incandescent bulb (a rotary knob or a sliding knob), and a triac that ignition timing is adjusted in response to an operation amount of the operation unit. A voltage supplied from the commercial power source is supplied to the incandescent bulb during an ignition time from the triac being turned on to the voltage becoming zero.    Patent Document 1: Japanese National Publication of International Patent Application No. 2005-524960
Wiring lines, as described above, for series-connecting the triac light dimmer and the incandescent bulb to the commercial power source are usually provided in a wall or at a back of a ceiling when a construction is built. Hence, there is a probability that change of structure of the wiring lines brings on destroy of the wall or the ceiling.
In contrast to this, if an LED illumination apparatus can be introduced introduce by using existing wiring lines and existing triac light dimmer, it is preferred in view of reducing initial costs relating to introduction of the LED illumination apparatus. Further, in a status that existing wiring structure is maintained, if a luminance and a color temperature of the LED illumination apparatus are adjustable, it is able to provide momentum to introduce the LED illumination apparatus instead of the traditional incandescent bulb to customers.
However, in an existing LED illumination system including a wiring line structure that a light dimmer and an LED illumination apparatus are series-connected to a commercial power source, there is no LED illumination system which is adjustable both of the luminance and the color temperature.